Bows and crossbows use at least one bowstring or cable to hold tension in their limbs and to shoot arrows and bolts. A traditional bow, recurve bow, or crossbow may have a single bowstring connecting the limbs. Compound bows and crossbows typically have a long bowstring that wraps around the end cams and is used to shoot the arrow, a control buss cable (CBC) connecting the bottom cam to the top cam (or vice versa), and a yoked buss cable (YBC) connecting the top axle to the bottom cam (or vice versa).
Materials used for strings in bows have evolved over time from sinew and horsehair to steel cabling, to current thermoplastic fibers and other modern materials bundled together. With almost all of these materials, the string is formed when multiple fibers are twisted or otherwise connected to each other in multiple strands. Each strand typically has similar material construction and length. The strands are then twisted together and entwined into the length and shape needed for the strings. Some portions may also be served in high-wear areas with serving material that wraps circumferentially around the diameter of the entwined strands.
Constructing a bowstring in this manner provides a bowstring with strand material that has high elastic modulus, high tensile break strength, high efficiency (often due to the strand material having low density), and the ability to separate the bundle of fibers into two side-by-side halves in a manner allowing the archer to place a peep sight into the string. The entwined string is also relatively easy to make since the string generally consists of one continuous strand of material (or in some cases two strands having the same material but different color) which is wrapped multiple times in a loop configuration without having to be cut along its length.
However, even these advanced strings lack resistance to abrasion and wear (which is one reason that certain portions are served), lack resistance to localized heat (i.e., they may melt easily when exposed to flame), and lack resistance to unintended cutting, particularly when the string is under high tension. For these and other reasons, archers and other sportsmen are constantly seeking improvements to bowstrings and cables used in archery equipment.